[ad_1]
Absolute temperature is measured from zero, the coldest temperature possible in nature. The Kelvin and Rankine scales are commonly used for scientific purposes. Water is used as a standard for temperature scales. Kinetic energy is related to temperature through an equation. At zero absolute temperature, there is still zero-point vibrational energy due to quantum mechanics.
Absolute temperature is the temperature measured using a scale starting at zero, with zero being the coldest temperature theoretically attainable in nature. There are two common absolute temperature scales derived from the Fahrenheit scale and the Celsius or centigrade scale. The first is the Rankine scale and the second is the Kelvin scale. While still used for ordinary purposes, both the Celsius and Fahrenheit scales, with their lower value below zero, are less desirable for computational scientific purposes. Zero degrees Rankine is identical to zero degrees Celsius.
Simply put, temperature is an indicator of how hot or cold an object is relative to other objects. As temperatures vary according to season and situation, a comprehensive scale of intermediate degrees has been developed to allow for comparisons. Two fixed points are needed to create a useful scale: a global and invariable standard. The logical choice on which to base standard temperature scales has been water, as it is abundant, accessible, changes state at certain temperatures, and can be easily purified. As mentioned above, however, temperature refers to heat, and heat refers at a more basic level to atomic and molecular motion.
Energy can be absorbed by atoms and molecules in various ways, such as through electron excitation, the transfer of an electron from a lower to a higher orbital state. In general, however, energy is absorbed and increases the motion of the entire atom or molecule. That energy – the energy that leads to “kinesis” or motion – is kinetic energy. There is an equation that relates kinetic energy to heat: E = 3/2 kT, where E is the average kinetic energy of a system, k is Boltzmann’s constant and T is the absolute temperature in degrees Kelvin. Note that in this calculation, if the absolute temperature is zero, the equation indicates that there is no kinetic energy or motion.
One type of energy actually still exists at zero degrees absolute temperature, even though this is not what the classical physical equation above indicates. The remaining motion is predicted by quantum mechanics and is associated with a specific type of energy called “zero-point vibrational energy.” Quantitatively, this energy can be calculated mathematically from the equation for a quantum harmonic oscillator and with knowledge of Heisenberg’s Uncertainty Principle. That principle of physics dictates that it is not possible to know both the position and momentum of very small particles, so if the position is known, the particle must retain a tiny vibrational component.
[ad_2]